JPS60152400A - Method for controlling drawing with liquid pressure press - Google Patents

Abstract

PURPOSE:To decrease the number of redrawing in the stage when a punch makes a stroke operation and presses and pushes a blank material to a die by regulating finely the speed of the stroke operation of the punch. CONSTITUTION:The stroke operation of a punch is finely regulated in speed by controlling the opening and closing of a servocontrol valve inserted into a liquid pressure circuit in the stage when the punch makes the stroke operation and presses and pushes a blank material to a die in drawing by a reduced pressure press. For example, the stroke length of about 1-2mm. is designated as the pitch for changing the stroke speed and the servocontrol valve is opened and closed in a fine range at every 1-2mm. stroke, by which the oscillative pressing force by the punch is exerted to the blank material.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for controlling drawing using a hydraulic press.

Conventionally, 11 drawing processes have been performed to form a deep container-shaped product by drawing process, but conventional re-drawing process requires as many punch and die sets as the number of drawing processes. In addition, the number of processes increases accordingly, and it takes a lot of time and effort.

This is because when the curving is repeated, the peripheral wall of the product becomes thinner than the bottom and at the same time becomes work hardened, so the drawing ratio must be gradually reduced as the number of drawings increases. If deeper drawing can be achieved in one drawing process, the number of re-drawing operations can be reduced to realize deep drawing processes, and the number of sets of punches and dies that need to be prepared can be reduced, allowing for more efficient drawing processes. Become.

The present invention is capable of reducing the number of times of re-drawing in drawing processing using a hydraulic press from one nail as described in 1.In other words, it is possible to perform deeper drawing in 2. The purpose of this method is to provide a drawing control method that allows the drawing process to be performed in a press. It is characterized by giving minute speed fluctuations to the stroke operation.

Next, embodiments of the present invention will be described with reference to the drawings.

In FIG. 1, numeral 1 is a hydraulic cylinder which is a source of stroke operation in a hydraulic press, 1a is its piston, 1b is a piston rod, and a drawing punch 2 is connected to the tip DHj5 of the rod 1b. 3 is die, 150 nIn
The punch 2, which is at the top dead center, is lowered in rapid traverse until it reaches the cable material W, and after it contacts the cable material W, it descends at a reduced drawing speed and reaches the bottom dead center. When the stroke speed is set, the rapid forward stroke speed and its interval (distance), and the deceleration stroke speed and its interval (distance) can be arbitrarily set in the setting section 11, respectively.

In this embodiment, the downward stroke speed of the punch 2 can be finely and arbitrarily realized by the degree of opening and closing of each of the valves 10b to 10f in the servo valve 10. The scheduled stroke speed is such that a pulse signal processed in the form of time/distance or distance Nt/time determines the degree of opening or closing of each of the valves 10b to 10f.

Next, in order to make the stroke speed of the punch 2 repeatedly become slow and fast after hitting the material W, the punch 2 punches the above at an appropriately equal pitch or another arbitrary pitch at an appropriately set descending stroke speed. The set downward stroke speed and a downward stroke speed that is slower or faster than the set downward stroke speed are alternately repeated to perform a stroke operation for throttling. Incidentally, the fourth position in the pitch where the speed repeats slowing and fastening may be any distance between 4 r and 115.

Therefore, in the oven loop control, command signals for the slow/sudden pitch amounts set in the setting section 11 and the respective stroke speeds are used as control signals for the drive control section 13 in the processing section 12, but in the illustrated close 1-loop control section 11, , when the punch 2 is lowered, each pinch amount and the stroke speed during that time are formed into a current position signal and a current speed signal, and these are compared with signals representing each scheduled value set in 1 above, A control signal for the drive control section 13 is formed in the processing section 12 using each scheduled value and a deviation value for correcting it.

Here, when forming a stroke speed pinch based on time, move the stroker end to the position detector 1.
It is detected by the signal of 4.

As an example of the stroke operation mode of the punch 2 according to the method of the present invention, for example, a stroke amount of about 1 to 2M1 is used as a pinch to change the stroke speed, and the servo valve 10 is opened in a minute range for each stroke of 1 to 211II11. [5I
This is to apply a J-like pressing force to the material W by the punch 2.

In this way, when drawing with a hydraulic press, if a vibratory pressing force (J is applied to the punch 2 that moves at a stroke speed), for example, the plate thickness decreases by lt, so the re-drawing rate (drawing ratio) is changed to the ratio +l13
If the target is too large, it will be possible to draw the rope smoothly even if it is difficult to draw due to breakage.
As a result, it becomes possible to perform drawing with high processing efficiency by increasing the re-drawing rate and reducing the number of times of re-drawing.

(1) In the drawing process using a 1llll pressure press, if the number of drawings is reduced by 11 and a drawn product similar to the product obtained by the conventional drawing process that requires a large number of re-drawings can be obtained, the necessary punch and die combination will be required. The number is reduced, which is advantageous in terms of equipment.

The present invention is as follows, and is extremely useful as a method for controlling the stroke operation of a punch in drawing process 1 using a hydraulic press.

[Brief explanation of drawings]

The figure shows an example of implementing the method of the present invention, and is a block diagram of a control system. 1. 1 mountain pressure cylinder, 2.. punch, 3. die, 4
・ Wrinkle presser, 5... switching valve, 6... oil pump, 9...
...Piping, 10.Servo valve, 11.Setting section, 12.
- Processing section, 13... Drive control section, 14... Position detector, 15 Oscillator, ]6... Speed detection section, 17. Speed calculation section, 18. Position calculation section agent Yoshikuni Koizumi

Claims (1)

[Claims] During drawing using a hydraulic press, when the punch strokes and presses the material against the die, a servo valve inserted in the hydraulic circuit opens and closes the servo valve to control the stroke of the punch at a minute speed. A drawing control method for a hydraulic press, characterized in that Jj can be increased.